FFT Libraries Hands-on Massimiliano Guarrasi, CINECA Casalecchio di Reno, 17/02/2016 Fast Fourier Transform (FFT) • FFTPACK • FFTW • 2Decomp&FFT • P3DFFT Fast Fourier Transform (FFT) FFTPACK FFTPACK is a package of Fortran subroutines for the fast Fourier transform. It includes complex, real, sine, cosine, and quarter-wave transforms . It is included in the general -purpose mathematical library SLATEC. Language: FORTRAN Availability: public domain Developers: Paul N. Swarztrauber, National Center for Atmospheric Research, Boulder, CO Distributors: NETLIB Ref.: The University of Tennessee at Knoxville and Bell Laboratories Fast Fourier Transform (FFT) FFTW (Fastest Fourier Transform in the West) FFTW is a C subroutine library for computing the discrete Fourier transform (DFT) in one or more dimensions, of arbitrary input size, and of both real and complex data (as well as of even/odd data, i.e. the discrete cosine/sine transforms or DCT/DST). The currently most used free library to compute DFTs. It uses both MPI and OpenMP. Language: C Availability: public domain Developers: Matteo Frigo and Steven G. Johnson. Distributors: FFTW Ref.: MIT Fast Fourier Transform (FFT) FFTW (Fastest Fourier Transform in the West) •Written in C (FORTRAN 77 /90 /2003 wrappers are included) •FFTW adapt itself to your system and your problem: It check both total memory, size of your array, cache size register, CPU type, … •… and it chose the best algorithm for you! •2 setps is required: •Plan creation •Execution •It supports FFTs for any different array size (< total memory) Fast Fourier Transform (FFT) 2Decomp&FFT The 2DECOMP&FFT library is a software framework in Fortran to build large-scale parallel applications. It is designed for applications using three-dimensional structured mesh and spatially implicit numerical algorithms. At the foundation it implements a general-purpose 2D pencil decomposition for data distribution on distributed-memory platforms. On top it provides a highly scalable and efficient interface to perform three -dimensional distributed FFTs . The library is optimised for supercomputers and scales well to hundreds of thousands of cores. It relies on MPI but provides a user-friendly VS programming interface that hides communication details from application developers. Language: FORTRAN Availability: public domain Developers: Ning LI. Distributors: 2decomp.org Ref.: HECToR Distributed Computational Science and Engineering (CSE) Service operated by NAG Ltd. http://www.2decomp.org/ Fast Fourier Transform (FFT) P3DFFT 3DFFT is a scalable software library implementing three-dimensional spectral transforms. It has been used in a variety of codes from many areas of computational science. It has been tested and used on many high-end computational system. It uses two-dimensional domain decomposition in order to overcome a scaling bottleneck of one -dimensional decomposition . This allows the programs with this library to scale well on a large number of cores, consistent with bisection bandwidth scaling of interconnect of the underlying hardware system. Language: C Availability: public domain Developers: Dimitry Pekurovsky. Distributors: 2decomp.org Ref.: San Diego Supercomputer Center (SDSC) at UC San Diego. https://code.google.com/p/p3dfft/.